html,
    body {
        margin: 0;
        padding: 0;
        height: 100%;
            overscroll-behavior: none;
    }

    :root {
        --bg: #fdfdfd;
        --text: #333;
        --subtext: #777;
        --accent: #1e90ff;
        --card-bg: #fff;
        --radius: 14px;
        --shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    }

    [data-theme="dark"] {
        --bg: #121212;
        --text: #eee;
        --subtext: #aaa;
        --accent: #4dabf7;
        --card-bg: #1e1e1e;
        --shadow: 0 4px 12px rgba(255, 255, 255, 0.04);
    }

    body {
        font-family: "Helvetica Neue", sans-serif;
        background: var(--bg);
        color: var(--text);
        padding: 5vh 5vw;
        display: flex;
        flex-direction: column;
        align-items: center;
        min-height: 100%;
        box-sizing: border-box;
        transition: background 0.3s ease, color 0.3s ease;
        position: relative;
    }

    h1 {
        font-size: 2rem;
        margin-bottom: 0.3rem;
    }

    p {
        font-size: 1rem;
        color: var(--subtext);
        margin-bottom: 2rem;
        text-align: center;
        max-width: 90%;
    }

    h2 {
        font-size: 1.2rem;
        color: var(--text);
        margin-top: 2rem;
        margin-bottom: 0.6rem;
        text-align: left;
        width: 100%;
        max-width: 700px;
        padding-left: 1rem;
    }

    .grid {
        display: grid;
        grid-template-columns: 1fr;
        justify-content: center;
        gap: 1rem;
        width: 100%;
        max-width: 700px;
    }

    .card {
        background: var(--card-bg);
        padding: 1.2rem;
        border-radius: var(--radius);
        box-shadow: var(--shadow);
        text-align: center;
        text-decoration: none;
        color: var(--text);
        font-size: 1rem;
        transition: all 0.3s ease;
        width: 100%;
        max-width: 320px;
        margin: 0 auto;
    }

    .card:hover {
        transform: translateY(-4px);
        box-shadow: 0 8px 18px rgba(0, 0, 0, 0.1);
        color: var(--accent);
    }

    footer {
        margin-top: 4rem;
        font-size: 0.85rem;
        color: var(--subtext);
        text-align: center;
    }

    /* 🌙/☀️ 切换按钮 */
    .toggle-theme {
        position: absolute;
        top: 1rem;
        right: 1rem;
        background: transparent;
        border: none;
        font-size: 1.5rem;
        cursor: pointer;
        transition: transform 0.3s ease;
    }

    .toggle-theme:hover {
        transform: rotate(20deg);
    }

    @media (min-width: 600px) {
        .grid {
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        }

        .card {
            margin: 0;
        }

        h1 {
            font-size: 2.4rem;
        }

        p {
            font-size: 1.1rem;
        }

        h2 {
            font-size: 1.3rem;
        }
    }


    @media (max-width: 600px) {
body {
padding: 4vh 4vw;
background: var(--bg); /* 默认使用变量 */
}

[data-theme="light"] body {
background: linear-gradient(145deg, #fefefe, #f0f4f8); /* 浅色背景增强 */
}

[data-theme="dark"] body {
background: linear-gradient(145deg, #121212, #1c1c1c); /* 深色渐变背景增强 */
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 0.2rem;
}

p {
    font-size: 0.9rem;
}

h2 {
    font-size: 1.1rem;
    margin-top: 1.5rem;
    padding-left: 1rem;
}

.grid {
    grid-template-columns: 1fr;
    gap: 1.2rem; /* 稍大间距形成呼吸感 */
}

.card {
    max-width: 280px;
    position: relative;
    overflow: hidden;
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
    background: var(--card-bg);
}

.card::before {
    content: attr(data-icon);
    position: absolute;
    top: -20px;
    right: -10px;
    font-size: 5rem;
    color: rgba(200, 200, 200, 0.15);
    z-index: 0;
    pointer-events: none;
}

.card {
    position: relative;
    z-index: 1;
}

footer {
    font-size: 0.8rem;
    margin-top: 3rem;
}
}